Cardiovascular fitness, body composition, and lipoprotein lipid metabolismin older men

Background. Lipoprotein lipids in older individuals are affected by family history of coronary artery disease (CAD), obesity, diet, and physical activ ity habits. Methods. The relationship of obesity and physical fitness ((V)over dot O(2) max) to lipoprotein lipids and postheparin lipases was examined in a cross- sectional study of 12 lean (LS) and 26 obese (OS) sedentary men and 18 mast er athletes (MAs) aged 65 +/- 1 years (mean +/- SE). The men were healthy, had no family history of CAD, and were weight stable on AHA dirts at the ti me of study. Results. (V)over dot O(2)max was similar in LS and OS men but higher in the MAs. The OS men had a higher percentage of body far (%BF), waist circumfer ence, and waist:hip ratio (WHR) than the MA and LS men, but MA and LS men d iffered only in waist circumference. Total and LDL-C levels were comparable , but HDL-C. HDL2-C, and %HDL2b subspecies were higher in MAs than in OS an d LS men, and in LS than in OS men. Triglyceride (TG) was similar in MAs an d LS men but higher in OS men. Across groups, two multiple regression analy ses models ((V)over dot O(2)max, RBF. and WHR or waist circumference) showe d that %BF and (V)over dot O(2)max independently predicted HDL-C and HDL2. whereas WHR predicted TG (r(2) = .45) more strongly than waist circumferenc e (r(2) = .39). Postheparin lipoprotein lipase activity (LPL) was comparabl e among groups and correlated independently with (V)over dot O(2)max;. Tota l postheparin lipolytic activity (PHLA), hepatic lipase activity (HL), and HL:PHLA ratio were similar in MAs and LS men but higher in OS men. In both multiple regression analysis models, only %BF predicted HL activity and the HL:PHLA ratio. The HL:PHLA ratio independently predicted HDL-C, HDL2-C, %H DL2b, %HDL3 subspecies, and the cholesterol:HDL-C ratio, whereas LPL activi ty predicted TG. Conclusions. Increased fitness and reduced total and abdominal fatness in M As are associated with lower HL and higher LPL activities, which may mediat e their higher HDL-C and lower TG levels relative to their sedentary peers.